I’m an 18 year old guy about to be 19 and I’m still struggling with acne around my forehead,mouth, and sides of my head?

just read this, then decide [ earthclinic.com/ailments/acne-natural-remedies/ ]

Do you eat a lot of processed food? I would avoid that.

Then go back to the dermatologist. Go back every 4 weeks or so until it is taken care of.

I have heard that if people become Vegans, their skin gets better.

Go back to your dermatologist and or doctor and pharmacist. They are all medically trained people. Would you rather take the advise of a welder? Or shop worker or somebody who is just here to bump up their 'answers score'?

Get a strong oral medication. Its super easy to keep up with and works behind the scenes to kill the infections that cause breakouts. I can't prescribe any off the top of my head since I've long since finished mine but a good oral medication coupled with a healthy lifestyle and thorough washing routine will do wonders.

1] Clean your face with coconut oil or olive oil, not soap and water. I know this is counter-intuitive, but it really helps. It helps clean out the pores, and it actually causes your skin to produce less oil.
Also, sunshine helps a lot. I never got rid of my acne until I got a job working outdoors. Mine was worse than yours, judging by your description.
And you could try a different dermatologist, or go back and hassle the one you went to.

I would suggest making a visit to a nutritionist. The problems that you are doing can be related directly to your diet.